A vast number of commercial products that are difficult to produce synthetically are today produced by fermenting organisms. Such products include alcohols (e.g., ethanol, methanol, butanol, 1,3-propanediol); organic acids (e.g., citric acid, acetic acid, itaconic acid, lactic acid, gluconic acid, gluconate, lactic acid, succinic acid, 2,5-diketo-D-gluconic acid); ketones (e.g., acetone); amino acids (e.g., glutamic acid); gases (e.g., H2 and CO2), and more complex compounds, including, for example, antibiotics (e.g., penicillin and tetracycline); enzymes; vitamins (e.g., riboflavin, B12, beta-carotene); and hormones. Fermentation is also commonly used in the consumable alcohol (e.g. beer and wine), dairy (e.g. in the production of yogurt and cheese), leather, and tobacco industries.
A vast number of processes of producing fermentation products, such as ethanol, by fermentation of sugars provided by degradation of starch-containing and/or lignocellulose-containing material are known in the art.
However, production of fermentation products, such as ethanol, from such plant materials is still too costly. Therefore, there is a need for providing processes that can increase the yield of the fermentation product and thereby reducing the production costs.